Just did a favorites list, as there's no real way to objectively rank games. In no particular order:
Mass Effect trilogy
Treating it as one game as I can't really pick a favorite, and it's all part of a continuous story anyway. This was just an excellent combination of some of the best storytelling in video game history, as well as seriously great gameplay to go along with it. You really develop a bond with the supporting characters, and some of the choices you have to make are just heartbreaking. The in-game universe (haha) they created and its lore are just so deep and mysterious for an original IP. Honestly one of the best science fiction universes out there.
Elder Scrolls Online
It's an MMO and therefore by definition plagued by continuous issues regarding performance, balance, etc. But even with all that, there's just something magical about having a fully voice-acted rendition of Tamriel that you can share with your friends. I've barely touched the single player games after getting hooked on ESO, and even after playing it non-stop for years, there's always new stuff to discover. I'm focusing on PVP during the current patch and it's a real blast. As said, it's far from perfect, but as my most-played game of all time, it deserves a place on the list.
Life is Strange: Before the Storm
While I enjoyed the original Life is Strange game, I was still very much on the fence about its writing. Dialogue seemed awkward, morally grey characters were few and inbetween, and the writers just tried to shoehorn as many controversial topics into each episode as possible. Its prequel, Before the Storm, is where this series really shines. It was created and written by a different (American) developer, and you can really notice how much more grounded the dialogue and characters feel. Much more attention is given to the emotional development of/between the characters, and the characters themselves feel a lot more ambiguous and multifaceted than in the original. At its core it is a teen drama, but the way in which it deals with relatable topics such as losing a lost one, losing touch with old friends, sudden infatuation with someone you've just met, and trying to make things work with people you don't necessarily like -- it was just surprising to me how maturely those were handled in a video game. If I have one complaint, it's that it's written so differently from the original that it becomes hard to see the games as a continuous story. If you can cope with the inherent awkwardness of video game storytelling, it's definitely something that'll have an impact on you one way or the other. Oh, and the soundtrack is second to none.
Mario Kart Wii
By now there's more balanced, more technically refined karting games out there, but it's still such a joy to go back to Mario Kart Wii. To me, it was the first game in the series that really hit the nail on the head, offering plenty of tracks, unlockables and options. I also liked that they switched out the annoying mini-boost system of MK64 and MKDD for a simpler, less intrusive system. While the item distribution could get out of hand at times, I also feel like MKW was a very skill-based game, and actually sitting down and learning how to tackle each track really paid off in terms of performance. Just avoid the motion controls.
Jazz Jackrabbit 2
Immortal 2D platformer. A lot of the reason I like this game is pure nostalgia, but it actually holds up quite well for a game that's older than some of our members. It was slower-paced, a bit less ADHD than its predecessor, while also having some great level design and aesthetics. Multiplayer was pretty fun as well, and with a userfriendly level editor, there's an infinite supply of content.
STALKER: Shadow of Chernobyl
It's one of those games that's just buggy and broken as hell but has too much charm to ignore. The atmosphere of this game was just through the roof, perfectly capturing what a post-apocalyptic Eastern Europe would feel like. How it subtly introduced the supernatural aspect also made it a truly frightening game in places. There's just a charm about this game that was not present in the sequels, nor in games that take place in similar settings, like Metro. How such a buggy and silly game could be so immersive is a testament to how great it was.
The Legend of Zelda: Ocarina of Time
Kind of an obligatory inclusion on 'best of/favorite' lists, but it's justified. I played Ocarina of Time shortly after it was originally released, and the game just blew my mind. Super Mario 64 had already done the pioneering work by providing a fully 3D-rendered sandboxy world, but Ocarina of Time enriched it with the RPG and storytelling elements to really make the world come to life. In a way, this was my first true 3D sandbox experience. The actual game design was solid as could be, and I don't think Nintendo could've done a better job transitioning Zelda to a 3D environment.
One of my first proper experiences with an RPG and it was amazing. The writing was great, the gameplay struck the right balance between intuitivity and depth, and the whole paper/storybook design was just so charming. I still need to go back and replay this sometime, as the 2/3 times I've completed it have all been a blast.
Back in the day it was often dismissed as a 'glorified tech demo', and while it was and still is an amazing technical feat, the gameplay has always been way underrated. It offered an amazing 'limited sand box', in which you followed a relatively linear path, but the game still offered you tons of options to tackle challenges in whichever way you saw fit. With the addition of mild 'superpowers' such as invisibility and extra strength, it made for a perfect playground to just fuck up enemies in countless different ways. It was a spiritual successor to Far Cry, and it is telling that Ubisoft arguably didn't get on this level with their attempts at making Far Cry sequels until FC5. A game that deserves to be remembered for more than just its fancy graphics.
American Truck Simulator
Sometimes I just need to relax, okay?